The present invention relates to patient safety cables. More particularly, the present invention pertains to bi-atrial and/or bi-ventricular patient safety cables such as for use with implantable leads and external medical devices and methods for their use.
The earliest instances of relatively prolonged cardiac stimulation, namely cardiac pacing, of a patient""s heart was effected through implanted cardiac leads attached to the heart muscle at distal electrode ends and extended through an incision in the patient""s skin. Initially, cardiac pacing was employed during postoperative recovery from cardiac surgery, and the attachment to the heart was made to the epicardium during the surgical procedure. To effect unipolar pacing of the heart, a single such implantable pacing lead was employed in conjunction with a subcutaneously implanted or skin surface return electrode coupled to an external lead conductor. To effect bipolar pacing of the heart, two such implantable pacing leads were implanted with the electrode ends implanted a distance apart. Implantable pacing leads have since evolved, for example, into permanent, unipolar and/or bipolar, endocardial and epicardial, pacing leads for chronic implantation in a patient.
Various circumstances require the connection of an external medical device to an implantable lead system, such as a system including unipolar and/or bipolar leads. Generally, cables are used to provide such connections. For example, such a situation arises during surgical implantation of an implantable device, e.g., a pacemaker or pacemaker-cardioverter-defibrillator, including a permanent cardiac lead or lead system, or, for example, during connection of a replacement implantable device with a pre-existing permanent cardiac lead or lead system. One particular situation includes an external pacing system analyzer, e.g., the MEDTRONIC(copyright) Model No. 5311 B PSA, that may be attached to the lead system to assess the performance thereof.
Further, for example, during patient hospitalization, a lead system may be implanted to allow monitoring and demand pacing of the heart as the patient recovers from cardiac surgery or another condition. It may be necessary at times to connect the lead system implanted in a patient to a temporary external pacemaker, programmer, analyzer, or other external medical device. For example, the proximal ends of the lead system may be attached to external medical device connector elements associated with MEDTRONIC(copyright) Model Nos. 5348 or 5388 external single chamber or dual chamber cardiac pacemakers. When a permanent or temporary pacing lead is to be connected, for example, a MEDTRONIC(copyright) Model 5433AN or the Model 5832/S reusable safety cable may be employed to make the connection between the temporary pacemaker and the proximal connector ends of the pacing lead.
In addition, the proximal ends of the lead system may be attached to the external medical device connector elements associated with the MEDTRONIC(copyright) Model No. 9790 Programmer. Connection to the programmer may be accomplished by using the MEDTRONIC(copyright) Model No. 5436 Analyzer Patient Cable, which is designed to connect the programmer""s analyzer subsystem to IS-1 implantable leads. The 5436 cable has two quick-connect bipolar lead connectors for dual chamber pacing and a spade-shaped indifferent electrode for unipolar pacing.
Recently, it has been proposed that various conduction disturbances involving both bradycardia and tachycardia of a heart chamber could benefit from stimulation applied at multiple electrode sites positioned in or about it in synchrony with a depolarization that has been sensed at at least one of the electrode sites. A number of proposals have been advanced for providing pacing therapies to alleviate these types of conditions and restore synchronous depolarization of right and left, upper and lower heart chambers. For example, commonly assigned U.S. Pat. No. 6,122,545, herein incorporated by reference, provides a multi-chamber cardiac pacing system method for providing synchronous pacing to the two upper heart chambers, to the two lower heart chambers, to three heart chambers, or to all four heart chambers. Such pacing systems require bi-atrial and/or bi-ventricular lead systems. These lead systems, in circumstances such as those described above, e.g., during hospitalization, may require operative connection to external devices, e.g., analyzer, external pacemaker, etc., for use in performing bi-atrial and/or bi-ventricular sensing/pacing functions. For example, during implant evaluation of bi-atrial and/or bi-ventricular configurations, sensing is analyzed and thresholds and impedances must be measured. Such measurements can be done in different configurations, namely single unipolar, single bipolar, common ring bipolar, etc.
The above-mentioned cables are designed to work with leads implanted in a single atrial and/or single ventricular chamber. For example, the MEDTRONIC(copyright) Model No. 5436 Analyzer Patient Cable is designed to connect an analyzer subsystem to two IS-1 implantable leads, e.g., one atrial lead and one ventricular lead. The cable has two quick-connect bipolar lead connectors and a spade-shaped indifferent electrode for unipolar pacing. The cable, however, is not suitable for use in bi-atrial and/or bi-ventricular sensing or pacing.
The systems and apparatus listed in Table 1 below, some of which are also described above, do not address the bi-atrial and/or bi-ventricular pacing/sensing problems discussed above, e.g., the inability to operatively connect bi-atrial and/or bi-ventricular implantable leads with an external medical device.
All references listed in Table 1, and elsewhere herein, are incorporated by reference in their respective entireties. As those of ordinary skill in the art will appreciate readily upon reading the Summary of the Invention, Detailed Description of the Embodiments, and claims set forth below, at least some of the devices and methods disclosed in the references of Table 1 and elsewhere herein may be modified advantageously by using the teachings of the present invention. However, the listing of any such references in Table 1, or elsewhere herein, is by no means an indication that such references are prior art to the present invention.
The present invention has certain objects. That is, various embodiments of the present invention provide solutions to one or more problems existing in the art with respect to patient safety cables. One such problem involves the inability to operatively connect bi-atrial and/or bi-ventricular implantable leads with an external medical device.
The bi-atrial and/or bi-ventricular patient safety cable and methods according to the present invention provide one or more of the following advantages. For instance, the present invention provides an xe2x80x9cin-parallelxe2x80x9d configured cable that operatively connects bi-atrial and/or bi-ventricular implantable leads (e.g., those leads used for multi-site pacing) with an external medical device. As such, for example, simultaneous pacing and sensing can be performed in both atrial chambers and/or both ventricular chambers.
Embodiments of an apparatus of the present invention may provide one or more of the following features: a patient safety medical device cable apparatus; a multi-conductor insulated external cable including a first cable portion, a second cable portion including at least one pair of external cable lead elements, and a Y-connector portion connected to a first end of the first cable portion; at least one pair of lo external cable lead elements that corresponds to one of a pair of bi-atrial implantable leads and a pair of bi-ventricular implantable leads; a Y-connector portion that includes at least one Y connection electrically connecting at least one pair of external cable lead elements with one or more conductors of a first cable portion; an external lead connector assembly electrically coupled to a second end of a first cable portion and configured to be electrically connected to an external medical device; two or more lead adaptors that are each configured for electrical connection to an implantable lead; external cable lead elements that are each terminated by a lead adaptor; an indifferent electrode lead element associated with at least a first cable portion and configured to be electrically connected with a patient; a second cable portion including a single pair of external cable lead elements, wherein the single pair of external cable lead elements corresponds to a single pair of bi-atrial implantable leads; a second cable portion including a single pair of external cable lead elements, wherein the single pair of external cable lead elements corresponds to a single pair of bi-ventricular implantable leads; a second cable portion including two pairs of external cable lead elements, wherein the two pairs of external cable lead elements correspond to a single pair of bi-atrial implantable leads and a single pair of bi-ventricular implantable leads; an external pacemaker including a connector assembly configured to mate with an external lead connector assembly; a programmer including a connector assembly configured to mate with an external lead connector assembly; and an analyzer including a connector assembly configured to mate with an external lead connector assembly.
Other embodiments of a method of the present invention may provide one or more of the following features: a method for electrically connecting one or more implantable leads to an external medical device; providing a patient safety medical device cable apparatus; providing a multi-conductor insulated external cable; providing an external cable including a first cable portion, a second cable portion including at least one pair of external cable lead elements corresponding to one of a pair of bi-atrial implantable leads and a pair of bi-ventricular implantable leads, and a Y-connector portion including at least one Y-connection electrically connecting at least one pair of external cable lead elements with one or more conductors of the first cable portion; providing an external lead connector assembly; providing two or more lead adaptors; attaching at least one lead adaptor to at least one implantable lead of a pair of bi-atrial implantable leads or a pair of bi-ventricular implantable leads; attaching an external lead connector assembly to an external medical device; and providing an indifferent electrode lead element associated with at least a first cable portion and configured to be electrically connected with a patient.
The above summary of the invention is not intended to describe each embodiment or every implementation of the present invention. Rather, a more complete understanding of the invention will become apparent and appreciated by reference to the following detailed description and claims in view of the accompanying drawings.